1. Field of the Invention
This invention relates to an external combustion engine for converting the displacement of a working liquid caused by the vapor volume change thereof into, and outputting it as, mechanical energy.
2. Description of the Related Art
A conventional external combustion engine is disclosed in Japanese Unexamined Patent Publication No. 2004-84523, in which a working liquid is sealed in a container and partly heated and vaporized by a heater, and the vapor of the working liquid thus vaporized is cooled and liquefied by a cooler, so that the displacement of the working liquid caused by the vapor volume change thereof is output by being converted into mechanical energy.
In this conventional external combustion engine, a heated portion of the container, in which the working liquid is vaporized, is formed of a straight tube and the heater is arranged on the outer peripheral surface of the heated portion thereby to heat and vaporize the working liquid.